Thermal spray coil for wire arc thermal spray machine

ABSTRACT

A thermal spray coil, shaped and sized to be compatible with a wire arc thermal spray machine, is disclosed. The thermal spray coil includes a wire of FeAlSi material. The wire includes 0.5 to 6 percent aluminum, 4 to 7 percent silicon, and a remaining balance of iron.

TECHNICAL FIELD

The present disclosure relates generally to a thermal spray coil employed in a wire arc thermal spray machine. More specifically, the present disclosure relates to a specific composition of a wire of the thermal spray coil employed in the wire arc thermal spray machine.

BACKGROUND

Various remanufacturing processes, such as a wire arc thermal spray process, are commonly known to refurbish and/or remanufacture used metallic components. In the wire arc thermal spray process, a wire of coating material is generally melted and applied on a metallic component to build up a surface that no longer satisfies the dimensional specifications of the metallic component. For instance, in case of a turbocharger, the thickness of a flange portion of the turbocharger may decrease with prolonged usage. Therefore, in order to remanufacture the turbocharger by the wire arc thermal spray process, the wire of coating material may be melted and applied on an external surface of the flange portion to return all dimensions to specifications. A composition and material of the wire of coating material applied to the metallic component must be selected, such that the wire of coating material exhibits characteristics that match and/or exceed the metallic material of the metallic component. For instance, in the case of the turbocharger, the wire of coating material must successfully sustain oxidation under 800 degrees Celsius, which is the operational temperature of the turbocharger.

Conventionally, the wire of Fe-22Cr-6Al material is used as the coating material in the wire arc thermal spray process to remanufacture the metallic component that has operational temperature of about 800 degree Celsius. While such materials of the wire have worked well, environmental concerns have motivated the industry to adopt a material of the coating material of the wire that avoid and/or limits the use of chromium and/or nickel.

United States Patent Application 2013/0337215 discloses a FeAlSiC material of the thermal spray wire as the coating material, to remanufacture a used component (metallic component). Such materials of the thermal spray wire may fail to oxidation when applied to the metallic component with 800 degree Celsius operational temperatures. Therefore, there exists a need for a composition and/or material of the thermal spray wire employed in the thermal spray process that may be environmentally friendly and may facilitate oxidation resistance at a temperature of about 800 degree Celsius.

SUMMARY OF THE INVENTION

Various aspects of the present disclosure are directed towards a thermal spray coil, shaped and sized to be compatible with a wire arc thermal spray machine. The thermal spray coil includes a wire of FeAlSi material. The wire includes 0.5 to 6 percent aluminum, 4 to 7 percent silicon, and a remaining balance of iron

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an exemplary turbocharger, in accordance with the concepts of the present disclosure;

FIG. 2 is a front view of the turbocharger of FIG. 1, which illustrates a flange portion of the turbocharger to be re-manufactured, in accordance with the concepts of the present disclosure; and

FIG. 3 is a side view of a wire arc thermal spray machine to remanufacture the flange portion of the turbocharger of FIG. 1 and FIG. 2, in accordance with the concepts of the present disclosure.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, there is shown an exemplary turbocharger 10 that may be required to operate at a temperature of about 800 degree Celsius. The turbocharger 10 includes a flange portion 12 that connects the turbocharger 10 to an exhaust manifold (not shown) of an engine (not shown). The flange portion 12 includes an external surface 14, and is made up of a metallic material. The metallic material may be, but is not limited to, aluminum, steel, iron casting, and/or the like. With continuous and prolonged operation, the external surface 14 of the flange portion 12 may wear out and the thickness of the flange portion 12 may decrease. In order to correct the thickness of the flange portion 12, and reuse the turbocharger 10, the flange portion 12 of the turbocharger 10 may require to be remanufactured. Although reference to the turbocharger 10 are made, concepts of the present disclosure should not be limited to the turbocharger 10 and may extend to any metallic component that may require to be operated at a temperature of about 800 degree Celsius. For example, concepts of the present disclosure may also be applied to the exhaust manifold (not shown) of the engine (not shown).

Referring to FIG. 3, there is shown a wire arc thermal spray machine 16, which is employed to remanufacture the turbocharger 10. For ease in reference, the wire arc thermal spray machine 16 will be referred to as the thermal spray machine 16, interchangeably hereinafter. The thermal spray machine 16 generally employs a thermal spray coil that includes a wire of FeAlSi material. The wire may be melted and sprayed on the external surface 14 of the flange portion 12 to remanufacture the turbocharger 10. In the current embodiment, however, a description of the thermal spray coil is supported by two thermal spray coils. Namely, a first thermal spray coil 18 and a second thermal spray coil 20 are included. Similarly, a description of the wire is supported by two wires. Namely, a first wire 22 and a second wire 24 are included. The first wire 22 is wound to form the first thermal spray coil 18, while the second wire 24 is wound to form the second thermal spray coil 20. Moreover, each of the first wire 22 and the second wire 24 may be melted and sprayed on the external surface 14 of the flange portion 12, to remanufacture the turbocharger 10.

In an embodiment of the present disclosure, the thermal spray machine 16 may employ the first thermal spray coil 18 with the first wire 22, the second thermal spray coil 20 with the second wire 24, a battery unit 26, and a thermal spray torch 28. The first thermal spray coil 18 and the second thermal spray coil 20, are shaped and sized to be compatible with the wire arc thermal spray machine 16. As is already mentioned, the first thermal spray coil 18 and the second thermal spray coil 20, respectively include a first wire 22 and a second wire 24 of coating material. Each of the first wire 22 and the second wire 24 are in electrical connection to the battery unit 26, via a control switch 30, and are fed through the thermal spray torch 28. The thermal spray torch 28 includes a first opening 32, a second opening 34, and a central gas passage 36. The central gas passage 36 is connected to a supply of pressurized air and/or pressurized gas. The first opening 32 and the second opening 34, respectively are adapted to receive the first wire 22 and the second wire 24 and route those wires continuously in front of the central gas passage 36, separated by a minimal gap. As the control switch 30 is actuated, a spark is produced between the first wire 22 and the second wire 24, which causes the first wire 22 and the second wire 24 to melt. A stream of molten metallic material is then projected to the external surface 14 of the flange portion 12. Therefore, the first wire 22 and the second wire 24 are deposited in the form of a coating layer 38 on the external surface 14 of the flange portion 12 By this process, a remanufacture of the turbocharger 10 occurs.

In the current embodiment, the first wire 22 and the second wire 24 of the first thermal spray coil 18 is made of the FeAlSi material. The first wire 22 and the second wire 24 include 0.5 to 6 percent aluminum, 4 to 7 percent silicon, and a remaining balance of iron. The specific composition of the first wire 22 and the second wire 24 is environment friendly and provides an ordered Body Centered Cubic (BCC) crystal structure that provides oxidation resistance at about 800 degree Celsius. Therefore, the coating layer 38, when applied to the external surface 14 of the flange portion 12, sustains relatively high operational temperatures of the turbocharger 10.

INDUSTRIAL APPLICABILITY

As part of the thermal spray remanufacturing process, an operator may identify the external surface 14 of the flange portion 12 of the turbocharger 10 that is required to be remanufactured. Thereafter, the operator may activate the thermal spray machine 16, via actuation of the control switch 30. This is to supply high electric voltage between the first wire 22 and the second wire 24. As the first wire 22 and the second wire 24 are separated by a minimal gap in the thermal spray torch 28, a spark is produced between the first wire 22 and the second wire 24. The spark melts both of the first wire 22 and the second wire 24. The molten first wire 22 and the molten second wire 24 are then deposited on the external surface 14 of the flange portion 12 of the turbocharger 10, in form of the coating layer 38. Furthermore, as the first wire 22 and the second wire 24 are made up of FeAlSi material, the coating layer 38 is also made up of the FeAlSi material, with composition of 0.5-6 percent aluminum, 4-7 percent silicon, and a balance of iron. Notably, the specific composition of the coating layer 38 is free from chromium and any other environmentally hazardous material. Moreover, the specific composition of the coating layer 38 provides an ordered BCC crystal structure that facilitates oxidation resistance at a high operational temperature of about 800 degree Celsius. Therefore, the specific composition of the first wire 22 and the second wire 24 facilitates an environment friendly and relatively high temperature oxidation resistant material of the coating layer 38 deposited on the turbocharger 10.

It should be understood that the above description is intended for illustrative purposes only and is not intended to limit the scope of the present disclosure in any way. Those skilled in the art will appreciate that other aspects of the disclosure may be obtained from a study of the drawings, the disclosure, and the appended claim. 

What is claimed is:
 1. A thermal spray coil shaped and sized to be compatible with a wire arc thermal spray machine, the thermal spray coil comprising: a wire of FeAlSi material, wherein the wire includes 0.5 to 6% aluminum, 4 to 7% silicon, and a remaining balance of iron. 